Installation for forming molded members of fibrous material

ABSTRACT

An installation for forming members of a fibrous material including cooperatively operating liquid-pervious basic and pressing forms forming a layer of material therebetween by expelling through the forms liquid from a solution containing the fibrous material; and a movable adjustable frame encompassing the basic form so as to control the extent of movement and pressing between the basic and pressing forms.

United States Patent [191 Posch et al.

[ Aug. 27, 1974 INSTALLATION FOR FORMING MOLDED MEMBERS OF FIBROUS MATERIAL [75] Inventors: Heinz Posch, Berlin; Wolfgang Nauert; Werner Lohner, both of Beckum, all of Germany [73] Assignee: AMIANTUS AG, Niederurnen,

Switzerland [22] Filed: Dec. 11, 1972 [21] Appl. No.: 314,039

[30] Foreign Application Priority Data Dec. 10, 1971 Germany 2162030 [52] US. Cl 425/85, 425/388, 425/396, 425/406, 425/450 [51] Int. Cl B29j 5/00, B28b 3/02 [58] Field of Search 425/84, 388, 73, 396, 406, 425/450, 85

[56] References Cited UNITED STATES PATENTS Harlan 425/84 X 2,915,801 12/1959 Harry 425/84 X 3,099,061 7/1963 Marchioli et a1. 425/84 3,158,904 12/1964 Groy et al 425/388 3,307,236 3/1967 Sirera 425/84 3,450,807 6/1969 Cheney 425/388 X 3,608,152 9/1971 Fink et a]. 425/450 C UX Primary Examiner-Robert L. Spicer, Jr. Attorney, Agent, or Firm-Waters, Roditi, Schwartz & Nissen 7 [57] ABSTRACT An installation for forming members of a fibrous material including cooperatively operating liquidpervious basic and pressing forms forming a layer of material therebetween by expelling through the forms liquid from a solution containing the fibrous material; and a movable adjustable frame encompassing the basic form so as to control the extent of movement and pressing between the basic and pressing forms.

8 Claim, 2 Drawing Figures INSTALLATION FOR FORMING MOLDED MEMBERS OF FIBROUS MATERIAL FIELD OF THE INVENTION The present invention relates to an installation or apparatus for forming molded members. More particularly, the invention relates to an installation for the manufacture of molded members constituted of a fibrous material, such as asbestos cement or the like, by positioning a layer of the fibrous material, which is contained in a liquid or aqueous suspension, against the surface of a liquid-pervious basic form corresponding to the finishing shape of the molded member.

The molding of a member; constituted of a layer of fibrous material, from fibrous material contained in a liquid or aqueous suspension, by depositing the material against the surface of a liquid-pervious or perforate basic form is effected by imparting a pressure differential to the opposite surfaces of the basic form, either by imposing a reduced pressure or vacuum to the surface of the basic form opposite to the surface on which the fibrous material layer is deposited, or by an increased pressure acting directed. on the fibrous materialcontaining layer. In both instances, the liquid, or aqueous portion of the suspension, is either aspirated through the perforations or apertures in the basic fonn, or pressed therethrough. Thus, the liquid or water con veyed through the basic form apertures deposits and positions the fibers-contained therein against the surface of the basic form so as to form a more or less compacted fibrous material layer.

After the formation of the required layer thickness, which is formed of the compacted, deposited material fibers, the basic form is removed from the installation, and the layer of fibrous material adhering thereto may be processed, if required, into final shape in another suitable apparatus.

DISCUSSION OF THE PRIOR ART In presently known installations of the type' described, the compression of fibrous material which is accumulated or deposited onto a basic form is effected primary by imposing a gaseous pressure medium thereon, or through application of a pressing form which is covered by an inflatable rubber layer. In both instances, disadvantages are encountered in that the wall thickness of the molded member being formed generally comes out rather uneven or erratic, in view of the fibers being deposited in the layer form at irregular rates. Another disadvantage of the known installations lies in that the removal of water or liquid needed for effecting the compression and formation of the layer of fibrous material can only be effected at one side thereof. Thus, in both instances, the molded fibrous material members produced in the prior art installations must be further reworked so as to provide a finished product.

SUMMARY OF THE INVENTION According to the present invention, there is provided a novel and improved apparatus for forming molded members of fibrous material being of constant thickness throughout, and with precise edge configurations, as well as being adapted to provide for the removal of any liquid or water, in which the fibrous material is suspended, from both sides of the layer, so asto readily.

obviate any disadvantages encountered in the prior art installations. Furthermore, the present installation provides for the forming of the molded fibrous material members without the need of further reworking thereof, by forming molded members having precise measurements, while concurrently effecting a significant reduction in the amount of time required for the compression of the material and the respective removal of any liquid from the formed layer of fibrous material.

In accordance with the present invention there is thus provided-an installation or apparatus constituted essentially of a rigid basic form of a liquid-pervious material, and a cooperative rigid pressing form also made of liquid-pervious material, both being gas-and-liquidpervious along the surfaces thereof,.and with the pressing form adapted to be conveyed toward the basic form. Preferably, the pressing form may be imparted a suitable surface configuration which is complementary with the surface configuration of the basic form.

- In a particularly advantageous structural embodiment of the invention, the basic form is encompassed by a suitable frame, which extends in the axial direction of pressing movement of the form toward the pressing form so as to overlap or extend beyond the thickness of the basic form and the initial thickness of the layer of fibrous material in the suspension, and which is axially displaceable with respect to-the basic form upon the latter being contacted in compressive engagement by the pressing form, until the required compressed thickness of the molded member is obtained. a

BRIEF DESCRIPTION OF THE DRAWING Reference is now had to the following detailed description of an exemplary embodiment of the present invention, taken in conjunction with the accompanying drawing, in which:

FIG. 1 illustrates a sectional elevational view of a fibrous material forming installation according to the present invention shown in an open position; and

FIG. 2 shows a sectional elevational view of a second embodiment of the forming installation in a closed position.

DETAILED DESCRIPTION Referring now in particular to FIG. lof the drawing, the forming installation of the present invention includes a basic liquid-pervious form 1 having a plurality of perforations or apertures extending therethrough, and which is adapted to be immersed in a fibrous material-containing aqueous suspension. A layer of fibrous material'6 formed from the suspension is adapted to be accumulated or deposited along the lower surface of the basic form I, for example, by imparting a vacuum or reduced pressure in the region 5 above the basic form 1. In order to attain the foregoing, as indicated previously, the basic form is provided with a plurality of apertures or perforations, and may preferably be covered by a suitable netting or filter cloth 3.

A pressing form 2, which is adapted to effect compression of the deposited layer of fibrous material 6 against the surface of the basic form 1, is made essentially of the same type of construction as basic form 1, and is adapted to be moved thereagainst by a suitable pressing device (not shown). Both the basic form 1 and the pressing form 2 may be constituted of rigid material, such as metal or hard synthetic plastic material.

The basic form 1 extends, in the direction of pres sure, into upwardly extending edge walls 7, which together with an upper closure wall 8 form the closed space or region 5. A suitable nozzle extends through closure wall 8, and communicates with conduits 9 which preferably extend toward the lowest points of the upper surface of the basic form 1, so as to provide for aspiration therethrough of at least portions of the air and of the liquid or water contained in the suspension.

A vertical frame 4 extends about the outer walls 7 of the basic form, the inner walls of the frame 4 being complementary to the outer surfaces of walls 7 and being axially slidable in regard thereto. The lower portion of frame 4 is dimensioned, in the direction of pressure thereof, so as to in addition to basic form 1, surround the fibrous material layer 6 deposited on the surface of the basic form prior to compression thereof by the pressing form 2.

Upon the basic form 1 and the pressing form 2 being brought together in the pressing sequence, as shown by the arrow in FIG. 1, the frame 4 is first contacted along the bottom surface thereof by the upper surface of lateral walls which support the pressing form 2, and is then moved upwardly, with respect to basic form 1, through the upward movement of pressing form 2 until it is finally positioned in contact with the bottom surface of the upper closure wall 8, as shown, for example, in FIG. 2 of the drawing. The height of the frame 4 is predetermined or adjusted whereby upon closing of the basic form 1 and pressing form 2 by the pressing sequence as shown in FIG. 2 of the drawing, a suitable gap or space is formed between the molding forms 1 and 2, corresponding essentially to the thickness of the molded member 6 which is being formed during the pressing. The particular advantage of frame 4 lies in that it encompasses the member being molded about its entire peripheral surface with rigid and exactly defined walls, whereby the present installation provides molded members having exact measured peripheral and thickness dimensions.

Since both the basic form 1 and pressing form 2 are provided with suitable perforations or apertures, the liquid or water contained in the fibrous material layer 6 being molded between the forms is expelled from both sides thereof, from the lower pressing form by falling and flowing therethrough, and from the upper pressing form by aspiration through conduits 9 and 9'. This, of course, will impart the required thickness to the layer of the fibers in the formed member.

If required, suitable compression springs 14 may be interposed between the upper front surfaces of the frame 4 and the bottom surface of upper wall 8 which, when no pressure is exerted against the frame 4 by the pressing form 2 will provide a positive force being exerted against the upper surface of frame 4 so as to posi- Upon completion of the compressing sequence, in

effect after the basic form I and pressing form 2 are separated, the frame 4, which during pressing has been upwardly moved against the lower surface of closure wall 8, will revert to the downward position shown in FIG. 1 due to its own gravitational weight so as to be in detached and spaced position relative to closure wall 8. In order to prevent the frame 4 from completely sliding away from contact with the walls 7 of the basic form I, the frame 4 is provided with an outwardly extending flange or collar 11 along the upper edge thereof, the flange being adapted to coact with a depending side wall 11 of closure wall 8, having an inwardly projecting flange 13 extending below the bottom of the flange 11. This in effect will provide for a guideway between the frame 4 and they entire structure of the basic form 1.

tion the latter in its downwardmost initial position relative to the basic form 1.

The downwardly projecting wall 12 and inwardly extending flange 13 may be constructed so as to be of yieldable construction whereby, if required, this provides for releasing of the frame 4 by flexing member 12 radially outwardly and permitting the flange 11 to slide down past the inwardly projecting flange 13.

In order to prevent, as required, any of the fiber material-containing suspension collecting on the bottom front edges of frame 4, which face toward the suspension when the basic form 1 is dipped into the suspension, and which could conceivably be detrimental to the exact molding of the fibrous layer, the latter of which is dependent upon the exact positioning of frame 4, the frame may be provided with a suitable ring or extension frame '15, the dimensions and positions of which correspond to the dimension and positions of the lower front surface of frame 4, and which abutagainst the lower frame edge before and during the immersion thereof into the fibermateriaI-containing suspension, and being removable just prior to the pressing form being brought into material pressing engagement with basic form 1. Alternatively, the foregoing may also be obtained by constructing and positioning frame 4 whereby its lower edge, when the basic form 1 is immersed in the suspension, may be moved backwardly to an extent behind the fibrous material layer on the surface of the basic form 1, whereby no suspension material of any appreciable amount accumulates on the frame surface.

In the embodiment of FIG. 2 of the drawing, which shows an installation constructed essentially similar to that of FIG. 1, and which operates in the same manner, a device may be provided which will prevent the inadvertent dropping down of the frame 4 upon opening of the mold after the fomiing of the molded member 6. The frame 4 thus may be maintained in its uppermost position in contact the lower surface of closure wall 8, by means of one or more suitable devices constituted essentially of a pivotable catch or lever 16 engageable with flange 11 and connected to the piston of a suitable hydraulic or pneumatic pressure cylinder 17 mounted on wall 8, and adapted to upon suitable actuation thereof to facilitate the release of catch 16 from the lower surface of flange 11. This will then permit the frame 4 to move downwardly in a controlled manner into the position shown in FIG. 1 upon separation between the basic form 1 and pressing form 2.

While there has been shown what is considered tobe the preferred embodiment of the invention, it will be obvious that modifications may be made which come within the scope of the disclosure of the specification.

What we claim is:

1. Installation for forming molded members of a fibrous material, such as asbestos cement or the like, comprising a Iiquid-pervious basic form adapted to have a layer of said fibrous material contained in a liquid suspension positioned against a surface thereof; a liquid-pervious pressing form adapted to be moved toward said material layer-covered surface of said basic form; means for providing a zone of reduced pressure on opposite side of said basic form so as to facilitate removal of said liquid from said material through said pervious basic and pressing forms and effect thickening of the fibrous material interposed between said forms; frame means encompassing the peripheral edges of said basic form, said frame means extending, in the direc tion of pressing, beyond said basic form edges, said frame means being axially slidable relative to said basic form so as to assume during the pressing together of said basic and pressing forms, a height depending beyond the edges of said basic form corresponding to the final thickness of the molded fibrous material formed between said basic and pressing forms, said reduced pressure zone comprising upstanding peripheral sidewalls extending from said basic form; an upper closure wall connected to said side walls; pressure medium conduit means in said closure wall communicating with said pressure zone; and outwardly projecting flange portions formed on at least part of the upper end of said frame means, said upper closure wall having depending wall portions juxtaposed over said flange portions so as to form guideway means therebetween, and inwardly extcndingprojections on said depending wall portions below said outwardly projecting flange portions.

2. installation as claimed in claim 1, said depending wall portions juxtaposed over said flange portions and the inwardly extending projections thereof being yieldframe means and said basic form.

3. Installation as claimed in claim 1, comprising spring means interposed between the upper surface of said outwardly projecting flange portions on said frame means and the lower surface of said upper closure wall.

upon said molded fibrous material attaining a predetermined thickness. 6. Installation as claimed in claim 1, comprising power-actuated catch means being fastened to at least the closure wall of said basic form, said catch means having inwardly extending clamp means adapted to releasably engagesaid flange portions on said frame means.

7. Installation as claimed in claim 6, said catch means being hydraulically actuated.

8. Installation as claimed in claim 6, said catch means being pneumatically actuated. 

1. Installation for forming molded members of a fibrous material, such as asbestos cement or the like, comprising a liquid-pervious basic form adapted to have a layer of said fibrous material contained in a liquid suspension positioned against a surface thereof; a liquid-pervious pressing form adapted to be moved toward said material layer-covered surface of said basic form; means for providing a zone of reduced pressure on opposite side of said basic form so as to facilitate removal of said liquid from said material through said pervious basic and pressing forms and effect thickening of the fibrous material interposed between said forms; frame means encompassing the peripheral edges of said basic form, said frame means extending, in the direction of pressing, beyond said basic form edges, said frame means being axially slidable relative to said basic form so as to assume during the pressing together of said basic and pressing forms, a height depending beyond the edges of said basic form corresponding to the final thickness of the molded fibrous material formed between said basic and pressing forms, said reduced pressure zone comprising upstanding peripheral sidewalls extending from said basic form; an upper closure wall connected to said side walls; pressure medium conduit means in said closure wall communicating with said pressure zone; and outwardly projecting flange portions formed on at least part of the upper end of said frame means, said upper closure wall having depending wall portions juxtaposed over said flange portions so as to form guideway means therebetween, and inwardly extending projections on said depending wall portions below said outwardly projecting flange portions.
 2. Installation as claimed in claim 1, said depending wall portions juxtaposed over said flange portions and the inwardly extending projections thereof being yieldably formed so as to permit separatioN between said frame means and said basic form.
 3. Installation as claimed in claim 1, comprising spring means interposed between the upper surface of said outwardly projecting flange portions on said frame means and the lower surface of said upper closure wall.
 4. Installation as claimed in claim 1, comprising removable ring means being positioned along at least some of the lower edges of said frame means, said ring means being of a height adapted to contact the upper surface of said pressing form before and during movement of the latter toward said basic form, and being removable prior to compression being effected between said basic and pressing forms.
 5. Installation as claimed in claim 1, said frame means comprising a stop means limiting the movement of said basic and pressing forms toward each other upon said molded fibrous material attaining a predetermined thickness.
 6. Installation as claimed in claim 1, comprising power-actuated catch means being fastened to at least the closure wall of said basic form, said catch means having inwardly extending clamp means adapted to releasably engage said flange portions on said frame means.
 7. Installation as claimed in claim 6, said catch means being hydraulically actuated.
 8. Installation as claimed in claim 6, said catch means being pneumatically actuated. 